The most common construction of a personal computer is a stand-alone desk-type computer using magnetic disk drives. Such computers, for example, the Apple MacIntosh computer, utilize a relatively large one-piece casing and significant power. This type of construction cannot be employed in so-called lap-type computers, let alone in an extremely small pocket-type computer. Such lap-type and pocket-type computers normally utilize memory cards and other miniature electronic components. So as to accommodate a display screen lap-type and pocket-type computers have employed a two-piece or multi-piece housing or casing with an upper casing containing the display screen.
In these devices each incremental part of the internal casing inch volume is important so to accommodate the required components. For example, the Zenith Supersport 286 Model includes a multi-piece casing in which a hinged upper casing incorporates a viewing screen. A lower casing from which a computer keyboard projects includes a raised rear position and a wide rear margin which permits the upper housing to be hinge rotated only 90.degree. from the keyboard housing Apparently there is a friction element in the side hinges which allow the upper position to be fixed at any angular position between 0.degree. and 90.degree..
Other two-part general usage containers utilize a friction-type hinge or a lock knob to keep a top half of a casing at an angular position with respect to a casing bottom half.